A Class/Division type of electrical codes and standards system is used in North America as the basis for classification of hazardous locations. Hazardous locations are divided into three Classes and two Divisions because hazards and methods of protecting electrical equipment against these hazards differ ...
Classification of hazardous locations (noxious and flammable orexplosive atmospheres)doi:Doc 1638-1970
Hazardous locations are defined in terms of Class, Division and Group, per the NEC. The definition of each is as follows: “CLASS I locations are those in which flammable Gases or Vapors are or may be present in the air in quantities sufficient to produce explosive or ignitable mixtures...
In North America, hazardous areas are separated by classes, divisions, and groups to define the level of safety required for equipment installed in these locations. Classes define the general form of the flammable materials in the atmosphere. Divisions define the probability of the presence of ...
内容提示: Definitions of Classes and Zones Hazardous Areas are locations where the potential for fire or explosion exists because of gases, dust, or easily ignitable fibers or flyings in the atmosphere. In North America, hazardous areas are separated by classes, divisions, and groups to define ...
(NFPA) 497 establish the Class/Division/Group system for classifying hazardous areas. This system allows for precise, standardized communication about the types of hazardous locations by classifying them based on the type of material (Class), the probability of explosion or ignition (Division), and...
5.0-Hazardous-Area-Classification
Class II locations are those that are hazardous because of the presence of combustible dust. CLASS II, DIVISION 1Class II, Division 1 locations include areas where combustible dust may be in suspension in the air under normal conditions in sufficient quantities to produce explosive or ignitable mix...
Group A, B, C or D - Indoor Hazardous Locations, Oil - immersed Type 9 Class II, Group E, F or G - Indoor Hazardous Locations, Air Break Equipment Type 10 Bureau of Mines Type 11 Corrosion - resistant and Drip - proof Oil - immersed - Indoor Equipment Type 12 Industrial use, Dust...
As explained in the definitions of the NEMA Types 7 and 9. The groups (indicated by letters), which follow the type class, indicate the gas or vapor atmospheres within the hazardous locations. 下列表格列出这些组包括的典型环境。 The following chart is a listing which gives the typical atmospher...